The present invention relates to an improved spin finish for synthetic fiber.
Upon emerging from a spinneret, many synthetic fibers require the application of a spin finish in order to further process the spun yarn. Because a spin finish may be present in a minimal layer on fiber, the spin finish acts as an interface between the fiber and the metallic surfaces such as guides and rollers which contact the fiber during such processing as drawing or relaxing.
Spin finishes comprising polyalkylene glycols with molecular weights of 300 to 1,000 are taught by commonly assigned U.S. Pat. No. 3,940,544; 4,019,990; and 4,108,781. See also U.S. Pat. No. 4,351,738.
U.S. Pat. No. 4,340,382 teaches a spin finish comprising polyalkylene glycol which is a block copolymer. Unfortunately, spin finishes comprising polyalkylene glycol block copolymers may form deposits on the metallic surfaces which they contact during manufacturing.
Spin finishes comprising polyalkylene glycols with molecular weights of greater than 1,000 are taught by U.S. Pat. Nos. 4,351,738; 4,552,671; and 5,507,989. Unfortunately, spin finishes comprising these higher molecular weight polyalkylene glycols also may form deposits on the metallic surfaces which they contact during manufacturing.
U.S. Pat. No. 4,442,249 teaches a spin finish comprising an ethylene oxide/propylene oxide block copolymer with a molecular weight greater than 1,000 and a lubricant of an alkyl ester or dialkyl ester or polyalkyl ester of tri-to hexaethylene glycol. Unfortunately, spin finishes comprising these block copolymers also may form deposits on the metallic surfaces which they contact during manufacturing.
Commonly assigned U.S. Pat. Nos. 3,681,244; 3,781,202; 4,348,517; 4,351,738; and 4,371,658 teach the use of polyoxyethylene castor oil in spin finishes.
A spin finish which is non-depositing and stable is needed in the art.
We have developed a spin finish which responds to the foregoing need in the art. The present spin finish composition comprises at least about 10 percent by weight based on the spin finish composition of components (a) and (b) having the formula
R1xe2x80x94(CO)xxe2x80x94Oxe2x80x94(CH(R2)xe2x80x94CH2xe2x80x94O)yxe2x80x94(CO)zxe2x80x94R3
wherein each of R1 and R3 is selected from the group consisting of hydrogen or an alkyl group having from one to 22 carbon atoms or an alkylene hydroxy group having from one to 22 carbon atoms,
x is zero or one,
R2 may vary within component (a) or component (b) and is selected from the group consisting of hydrogen or an alkyl group having from one to four carbon atoms,
y is zero, or from one to 25, and
z is zero or one,
in component (a), x and z are equal to zero and the average molecular weight of component (a) is less than or equal to 1,900 and if R2 varies, component (a) is a random copolymer; and
in component (b), at least x or z is equal to one or component (b) is a complex polyoxyethylene glyceride-containing compound having greater than 10 polyoxyethylene units; and
up to five percent by weight based on the spin finish composition of component (c) of an alkoxylated silicone.
The present invention is advantageous because the spin finish is substantially non-depositing and stable.
Other advantages of the present invention will be apparent from the following description and attached claims.
Component (a) of the present spin finish composition has the formula
R1xe2x80x94(CO)xxe2x80x94Oxe2x80x94(CH(R2)xe2x80x94CH2xe2x80x94O)yxe2x80x94(CO)zxe2x80x94R3
wherein each of R1 and R3 is selected from the group consisting of hydrogen or an alkyl group having from one to 22 carbon atoms, x and z are zero, R2 may vary and is selected from the group consisting of hydrogen or an alkyl group having from one to four carbon atoms, and y is zero, or from one to 25. The average molecular weight of component (a) is less than or equal to 1,900.
Preferably, the average molecular weight of component (a) is greater than 500. More preferably, the average molecular weight of component (a) is less than about 1,500.
Preferably, in component (a), each of R1 and R3 is selected from the group consisting of hydrogen or an alkyl group having from one to ten carbon atoms, R2 varies and is selected from the group consisting of hydrogen and an alkyl group having one or two carbon atoms, and y is zero or between one to 20. The term xe2x80x9cR2 variesxe2x80x9d means that R2 may be hydrogen and methyl, hydrogen and ethyl, or methyl and ethyl. More preferably, in component (a), each of R1 and R3 is selected from the group consisting of hydrogen or an alkyl group having from one to five carbon atoms atoms, R2 is selected from the group consisting of hydrogen and an alkyl group having one carbon atom, and y is zero or between one to 16.
Preferred component (a) is a so-called random copolymer, and more preferably, a random copolymer made from ethylene oxide and propylene oxide. Ethylene oxide and propylene oxide are reacted simultaneously to form mixed polyalkylene glycol compounds. Preferred compounds are condensation products of about 30 to about 70 percent by weight ethylene oxide and about 30 to about 70 percent by weight propylene oxide and are terminated with an alcohol having one to four carbon atoms. Useful random copolymers are commercially available.
Preferably, component (a) is present in an amount of at least about 10 percent by weight based on the spin finish composition. More preferably, component (a) is present in an amount of at least about 20 percent by weight based on the spin finish composition.
Component (b) of the present spin finish has the formula
R1xe2x80x94(CO)xxe2x80x94Oxe2x80x94(CH(R2)xe2x80x94CH2xe2x80x94O)yxe2x80x94(CO)zxe2x80x94R3
wherein each of R1 and R3 is selected from the group consisting of hydrogen or an alkyl group having from one to 22 carbon atoms or an alkylene hydroxy group having from one to 22 carbon atoms, x is zero or one, R2 may vary and is selected from the group consisting of hydrogen or an alkyl group having from one to four carbon atoms, z is zero or one, and at least x or z is equal to one. Component (b) may be a mixture of components or may be a complex polyoxyethylene glyceride-containing compound having greater than 10 polyoxyethylene units.
Preferably, in component (b), each of R1 and R3 is selected from the group consisting of hydrogen or an alkyl group having from one to 18 carbon atoms or alkylene hydroxy group having from one to 18 carbon atoms, R2 does not vary and is selected from the group consisting of hydrogen or an alkyl group having one or two carbon atoms, and y is from 5 to 25. More preferably, in component (b), x is one and z is zero.
Useful complex esters are commercially available.
The most preferred component (b) is a polyoxyethylene glyceride-containing compound having greater than 10 polyoxyethylene units and the most preferred polyoxyethylene glyceride-containing compound having greater than 10 polyoxyethylene units is ethoxylated castor oil.
Preferably, component (b) is present in an amount of at least about five percent by weight based on the spin finish composition.
Component (c) is an alkoxylated silicone. Preferably, the alkoxylated silicone has a siloxane backbone with organic polyalkylene oxide pendants. Useful alkoxylated silicones are commercially available. The alkoxylated silicone is used in an amount of up to about five percent by weight based on the spin finish composition.
The present spin finish may be used on any synthetic fiber. Useful synthetic materials include polyesters and polyamides. Useful polyesters include linear terephthalate polyesters, i.e., polyesters of a glycol containing from 2 to 20 carbon atoms and a dicarboxylic acid component containing at least about 75% terephthalic acid. The remainder, if any, of the dicarboxylic acid component may be any suitable dicarboxylic acid such as sebacic acid, adipic acid, isophthalic acid, sulfonyl-4,4xe2x80x2-dibenzoic acid, or 2,8-dibenzofurandicarboxylic acid. The glycols may contain more than two carbon atoms in the chain, e.g., diethylene glycol, butylene glycol, decamethylene glycol, and bis-1,4-(hydroxymethyl)cyclohexane. Examples of linear terephthalate polyester include poly(ethylene terephthalate); poly(butylene terephthalate); poly(ethylene terephthalate/5-chloroisophthalate)(85/15); poly(ethylene terephthalate/5-[sodium sulfo]isophthalate)(97/3); poly(cyclohexane-1,4-dimethylene terephthalate), and poly(cyclohexane-1,4-dimethylene terephthalate/hexahydroterephthalate). These starting materials are commercially available.
Another useful polymer is the copolymer taught by commonly assigned U.S. Pat. No. 5,869,582. The copolymer comprises: (a) a first block of aromatic polyester having: (i) an intrinsic viscosity which is measured in a 60/40 by weight mixture of phenol and tetrachloroethane and is at least about 0.6 deciliter/gram and (ii) a Newtonian melt viscosity which is measured by capillary rheometer and is at least about 7,000 poise at 280xc2x0 C.; and (b) a second block of lactone monomer. Examples of preferred aromatic polyesters include poly(ethylene terephthalate) (xe2x80x9cPETxe2x80x9d), poly(ethylene naphthalate) (xe2x80x9cPENxe2x80x9d); poly(bis-hydroxymethylcyclohexene terephthalate); poly(bis-hydroxymethylcyclohexene naphthalate); other polyalkylene or polycycloalkylene naphthalates and the mixed polyesters which in addition to the ethylene terephthalate unit, contain components such as ethylene isophthalate, ethylene adipate, ethylene sebacate, 1,4-cycohexylene dimethylene terephthalate, or other alkylene terephthalate units. A mixture of aromatic polyesters may also be used. Commercially available aromatic polyesters may be used. Preferred lactones include xcex5-caprolactone, propiolactone, butyrolactone, valerolactone, and higher cyclic lactones. Two or more types of lactones may be used simultaneously.
Useful polyamides include nylon 6; nylon 66; nylon 11, nylon 12, nylon 6,10, nylon 6,12, nylon 4,6, copolymers thereof, and mixtures thereof.
The synthetic fiber may be produced by known methods for making industrial fiber. For example, commonly assigned U.S. Pat. Nos. 5,132,067 and 5,630,976 teach methods for making dimensionally stable PET. After the synthetic fiber emerges from a spinneret, the present spin finish may be applied to the synthetic fiber by any known means including bath, spray, padding, and kiss roll applications. Preferably, the present spin finish is applied to the synthetic yarn in an amount of about 0.2 to about 1.5 percent by weight based on the weight of the synthetic yarn.